JP7322746B2 - Vehicle speed control device - Google Patents

Description

The present invention includes a plurality of torque applying devices connected to a predetermined rotating member so as to be able to transmit torque, and by controlling the torque of these torque applying devices, the rotational speed of the predetermined rotating member follows a target rotational speed. The present invention relates to a rotation speed control device for a vehicle that allows the vehicle to rotate.

In patent document 1, in order to suppress deterioration of emissions due to changes in engine torque when feedback control is performed on a torque obtained by synthesizing engine torque and motor torque, a feedback gain of engine torque is set to a feedback gain of motor torque. A control device for a hybrid vehicle is described which is configured to be set to be smaller than the gain.

Patent Document 2 discloses a hybrid vehicle in which an engine, a motor, and an output member are connected so as to be capable of differential rotation, and the engine speed is controlled to follow a target speed by controlling the motor speed. A controller is described. This control device reduces the engine speed in order to prevent inconsistency between the engine torque control and the motor torque control due to the fact that the response of the engine is slower than the response of the motor. In the case of temporary change, the target rotation speed for determining the engine torque is maintained at the target rotation speed before the engine rotation speed is temporarily changed, and the target rotation speed for determining the motor torque is changed to the engine speed. It is configured to change the rotation speed following the target rotation speed to be actually changed.

Patent Document 3 discloses an engine, a clutch mechanism connected to the output shaft of the engine, a motor connected to the engine via the clutch mechanism, and a torque converter connected to the output shaft of the motor. A control system for a hybrid vehicle is described. In a hybrid vehicle configured in this way, the reaction torque characteristic of the torque converter is non-linear, so there is a possibility that the accuracy of motor rotation speed control will be reduced. Therefore, the control device described in Patent Document 3 feedback-controls the motor torque based on the difference between the actual value and the target value of the input rotation speed of the torque converter, and the allowable rotation speed fluctuation amount and the torque of the motor at that time It is configured to set the feedback gain based on the kinematic characteristics of the converter.

JP-A-06-233411 JP 2013-189034 A JP 2011-194941 A

The control device described in Patent Literature 1 sets a small feedback gain for the engine torque to suppress deterioration of emissions due to a change in the operating point of the engine due to a sudden change in the engine torque, and feedback of the motor torque. It sets a large gain. However, if the motor torque before feedback control is increased or decreased to the vicinity of the motor torque limit value, the amount by which the motor torque can be changed becomes smaller, and the engine torque and the motor torque are reduced. may not be able to follow the required torque.

Further, the control device described in Patent Document 2 is based on the premise that the torque response of the motor is better than the torque response of the engine, and when the engine speed is temporarily changed, the engine torque is not changed, and the target rotation speed for determining the motor torque is set by changing it to the rotation speed when the engine rotation speed is temporarily changed. ing. However, when the motor speed is high, there is a possibility that the rate of change of the motor torque may be restricted in order to prevent excessive temperature rise of the inverter for controlling the motor torque. In such a case, the responsiveness of motor torque decreases. On the other hand, when controlling the engine torque by changing the ignition timing for igniting the mixture of air and fuel supplied to the engine, the higher the engine speed, the more the engine torque responsiveness. becomes better. Therefore, when the rotational speeds of the engine and the motor are high, the engine torque responsiveness may be better than the motor torque responsiveness. Therefore, if the motor torque is controlled regardless of the operating state of the engine or motor, there is a possibility that the synthesized torque cannot be changed quickly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical problem, and is a vehicle rotation speed control apparatus capable of appropriately performing feedback control for causing the rotation speed of a predetermined rotating member to follow a target rotation speed. It is intended to provide

In order to achieve the above objects, the present invention comprises an engine and a motor coupled to an output shaft of the engine , and controls a combined torque obtained by synthesizing torques output from the engine and the motor. A rotation speed control device for a vehicle configured to adjust the rotation speed of the output shaft to a target rotation speed by performing , the controller obtains a target amount of change in the resultant torque required to reduce a difference between an actual rotation speed of the output shaft and a target rotation speed of the output shaft; and the target rotational speed of the output shaft, the torque responsiveness of the motor is higher than the torque responsiveness of the engine according to the operating conditions of the engine and the motor. is also good, the amount of change in the torque applied to the output shaft by the motor is determined , and the target amount of change in the combined torque and the amount of change in the torque applied to the output shaft by the motor and the amount of change in the torque applied to the output shaft by the engine is determined, and the difference between the actual rotation speed of the output shaft and the target rotation speed of the output shaft is reduced. determining an amount of change in the torque applied to the output shaft by the engine when the torque responsiveness of the engine is better than the torque responsiveness of the motor, according to the operating states of the engine and the motor; The amount of change in the torque applied to the output shaft by the motor is determined based on the target amount of change in the combined torque and the amount of change in the torque applied to the output shaft by the engine. and

Further, in the present invention, the controller determines that the torque responsiveness of the motor is better than the torque responsiveness of the engine when the number of revolutions of the engine is less than a predetermined number of revolutions. and if the number of revolutions of the engine is equal to or higher than the predetermined number of revolutions, it may be determined that the torque responsiveness of the engine is better than the torque responsiveness of the motor. .

Further, in the present invention, the engine is configured such that an ignition timing for igniting a mixture of supplied air and fuel is controlled according to a rotation angle of an output shaft of the engine, and the ignition timing is set in advance. The torque applied to the output shaft may be changed by changing the predetermined timing.

Further, in the present invention, the engine is configured to supply fuel to the engine according to the rotation angle of the output shaft, and the amount of fuel supplied to the engine acts on the output shaft. It may be configured to change the torque applied.

According to this invention , an engine and a motor are provided to apply torque to the output shaft of the engine . Therefore, by controlling the torque of at least one of the engine and the motor , the rotation speed of the output shaft can be changed. A controller that controls the output torque of the engine and the motor selects the output shaft with better torque responsiveness when reducing the difference between the actual rotation speed of the output shaft and its target rotation speed. Determine the amount of change in the applied torque . Therefore , it is possible to preferentially output the torque from the engine or motor suitable for outputting the feedback torque , and perform feedback control for causing the actual rotation speed of the output shaft to follow the target rotation speed. can be done properly.

It is a mimetic diagram for explaining an example of vehicles in an embodiment of this invention. 4 is a time chart showing changes between the actual value of the engine speed and the target speed during an upshift; 4 is a flowchart for explaining a control example for selecting a torque adding device for outputting feedback torque according to torque responsiveness; FIG. 5 is a diagram showing the order of control means with good torque responsiveness when the engine speed is low and when the engine speed is high. 4 is a flowchart for explaining a control example for selecting a torque adding device for outputting feedback torque according to the amount of change in torque that can be output; 4 is a flowchart for explaining a control example for selecting a torque adding device for outputting feedback torque based on whether or not driving force is prioritized;

FIG. 1 shows a schematic diagram for explaining an example of a vehicle according to an embodiment of the invention. A vehicle Ve shown in FIG. It is a hybrid vehicle capable of four-wheel drive provided with the device 5.

The engine 1 can adopt various engines such as conventionally known gasoline engines and diesel engines, and the output torque is changed by controlling the fuel injection amount, the intake air amount, or the ignition timing. configured to be able to Further, the fuel cut control can be executed by stopping the supply of fuel to the engine 1 and applying braking torque to the output shaft 6 by friction torque, pumping loss, etc. caused by rotating the engine 1 together. ing. In the following description, the torque generated by the engine 1 is simply referred to as engine torque.

Specifically, the ignition timing of the engine 1 is controlled to be retarded from the optimum ignition timing (minimum advance for the best torque), or the fuel injection amount is reduced (including stoppage of fuel supply), or , the engine torque can be reduced by reducing the amount of intake air (including closing the throttle valve). Conversely, the ignition timing of the engine 1 is controlled to the optimum ignition timing, or if the optimum ignition timing cannot be controlled for some reason, the ignition timing is advanced from the optimum ignition timing to increase the engine torque. Alternatively, the engine torque can be increased by increasing the fuel injection amount or by increasing the intake air amount. The optimal ignition timing described above corresponds to "predetermined timing" in the embodiments of the present invention.

The ignition timing control that changes the engine torque by changing the ignition timing and the fuel injection amount control that changes the fuel injection amount to change the engine torque are controlled by the engine speed, more specifically, the output shaft of the engine 1. 6, the engine torque changes faster as the engine speed increases. That is, the responsiveness of the engine torque is improved. On the other hand, by changing the throttle opening or, if the engine 1 is provided with a supercharger, by switching the operation state of the supercharger, the amount of intake air is changed to change the engine torque. The intake air amount control is controlled without depending on the engine speed, and the change speed of the engine torque becomes slower than when the ignition timing control and the fuel injection amount control are executed. That is, the responsiveness of the engine torque is inferior to that of ignition timing control and fuel injection amount control.

Each of the motors 2 and 4 can be composed of a conventionally known AC motor such as a synchronous motor having a rotor provided with permanent magnets, and functions as a motor that outputs torque so as to increase the rotation speed of the output shaft. In addition, it has a function as a generator that outputs torque so as to reduce the rotation speed of the output shaft and converts a part of the power of the output shaft into electric power.

Inverters 7 and 8 are connected to these motors 2 and 4, respectively, and a power storage device 9 is connected via these inverters 7 and 8. As shown in FIG. These inverters 7 and 8 are provided with switching elements, such as diodes and transistors, connected in parallel. and its frequency. Also, the inverters 7 and 8 are connected so as to be able to exchange electric power with each other.

The rear driving device 3 is configured to control the torque transmitted to the pair of rear wheels 10, and in the example shown in FIG. Specifically, the rotor of the rear motor 2 is integrated with the output shaft 6 of the engine 1 by spline engagement or the like, so that the torque of the rear motor 2 can be applied to the output shaft 6. The engine 1 and the rear motor 2 may be connected to the output shaft 6 via a gear pair or the like so that torque can be transmitted, or torque may be transmitted to the output shaft 6 via a transmission mechanism such as a torque converter or a clutch mechanism. They may be communicably connected.

The output shaft 6 of the engine 1 corresponds to the "predetermined rotating member" in the embodiment of the present invention, and extends through the rear motor 2 to the rear side of the vehicle Ve. 11 is provided. The clutch mechanism 11 is for interrupting the transmission of torque between a rear transmission mechanism 12 or rear wheels 10, the engine 1, and the rear motor 2, which will be described later, and employs a mesh clutch mechanism or a friction clutch mechanism. can do.

An output shaft 13 of the clutch mechanism 11 is connected with a rear transmission mechanism (Re-T/M) 12 for controlling the rotational speeds of the engine 1 and the rear motor 2 . The rear transmission mechanism 12 includes a plurality of engagement mechanisms, and is a stepped transmission mechanism that sets a predetermined gear stage by engaging a predetermined one of the engagement mechanisms, or a gear shift mechanism. A stepless transmission mechanism that can continuously change the ratio can be employed. The rear transmission mechanism 12 is coupled to the pair of rear wheels 10 via a rear differential gear unit 14 and a rear drive shaft 15 so that torque can be transmitted.

Synthetic torque obtained by synthesizing the torque output from the engine 1 (hereinafter referred to as engine torque) and the torque output from the rear motor 2 (hereinafter referred to as motor torque) is input to the rear transmission mechanism 12. be. Then, the input torque is increased or decreased according to the gear ratio set in the rear transmission mechanism 12 and transmitted to the pair of rear wheels 10 . Therefore, by changing either one of the engine torque and the motor torque, the torque input to the rear transmission mechanism 12 and the torque transmitted to the pair of rear wheels 10 can be changed.

This engine torque can be determined, for example, based on the rotational speed of the engine 1 so that the operating point of the engine 1 is a fuel efficient operating point. Also, the motor torque is set to the difference between the target torque to be input to the rear transmission mechanism 12 and the engine torque, for example, based on the required driving force and the gear ratio of the rear transmission mechanism 12. can do. That is, if the target torque is larger than the engine torque, the rear motor 2 outputs the insufficient torque, and if the target torque is smaller than the engine torque, the rear motor 2 outputs braking torque to cancel the excess torque.

On the other hand, the front driving device 5 is configured to control the torque transmitted to the pair of front wheels 16. In the example shown in FIG. ) 18 are connected. Like the rear transmission mechanism 12, the front transmission mechanism 18 can be composed of a stepped transmission mechanism or a stepless transmission mechanism. The front transmission mechanism 18 is coupled to the pair of front wheels 16 via a front differential gear unit 19 and a front drive shaft 20 so that torque can be transmitted.

An electronic control unit (hereinafter referred to as ECU) 21 is provided for controlling the engine 1, the motors 2 and 4, the transmission mechanisms 12 and 18, and the clutch mechanism 11 described above. The ECU 21 is mainly composed of a microcomputer in the same manner as a conventionally known electronic control unit, and receives signals from various sensors provided on the vehicle Ve, and stores the input signals and pre-stored signals. Command signals are sent to the engine 1, the motors 2 and 4 (specifically, the inverters 7 and 8), the transmission mechanisms 12 and 18, and the clutch mechanism 11 based on the calculation formula, map, control flow, etc. to output

Examples of signals input to the ECU 21 include a signal from a vehicle speed sensor that detects vehicle speed, a signal from a sensor that detects the crank angle of the engine 1, a signal from a sensor that detects the rotation speed of the rear motor 2, and a signal from a sensor that detects the rotation speed of the front motor 4. These include a sensor signal for detection, a signal for an accelerator opening sensor for detecting the operation amount of an accelerator pedal (not shown), a sensor signal for detecting the remaining charge of the power storage device 9, and the like. By detecting the crank angle of the engine 1 and multiplying the detected value by a predetermined coefficient, the rotational speed of the engine 1 can be obtained.

Further, the maps stored in the ECU 21 include a driving force map for determining the driving force required for the vehicle Ve based on the accelerator opening and the vehicle speed, and a driving force map for determining the driving force required for the vehicle Ve based on the required driving force and the vehicle speed. , a shift map for determining the gear ratio set by the front transmission mechanism 18, and the like. Furthermore, the control flow stored in the ECU 21 is such that, for example, when shifting due to a change in the gear ratio determined based on the shift map, the output of the engine 1, the rear motor 2, or the front motor 4 during the shift transition period. It is a control flow for controlling torque and rotation speed.

The above-described vehicle Ve has an engine running mode in which engine torque is transmitted to the rear wheels 10 to run, and an engine running mode in which transmission of torque between the engine 1 and the rear wheels 10 is cut off and the driving torque of the front motor 4 is transmitted to the front wheels 16. It is possible to set an EV driving mode in which the vehicle is driven by In addition, in the engine running mode, it is possible to run by adding motor torque to the engine torque, to run by regenerating a part of the power of the engine 1 with the rear motor 2, and furthermore, to run with power transmitted from the engine 1 and the rear motor 2. In addition to the driving force for the rear wheels 10 generated by the torque applied to the front motor 4, the torque can be transmitted from the front motor 4 to the front wheels 16 to generate driving force for running.

Furthermore, in the EV running mode, the clutch mechanism 11 is released, the engine 1 is driven, the power of the engine 1 is converted into electric power by the rear motor 2, and the converted electric power is energized to the front motor 4 to run. Alternatively, the front motor 4 can be energized from a power storage device (not shown) to run.

When driving with the above-described engine driving mode set, if the required driving force or the vehicle speed changes, the rear transmission mechanism 12 is operated to drive the engine 1 at an operating point at which the fuel efficiency of the engine 1 is good. change the gear ratio of the When changing the gear ratio of the rear transmission mechanism 12, first, the transmission of torque between the engine 1 and the rear motor 2 and the rear transmission mechanism 12 is interrupted by switching the clutch mechanism 11 to the released state, and then , to change the gear ratio of the rear transmission mechanism 12 . When the gear ratio of the rear transmission mechanism 12 is changed in this manner, the rotation speed of the output shaft 13 of the clutch mechanism 11 becomes the rotation speed based on the gear ratio and the vehicle speed after the rear transmission mechanism 12 is shifted.

Therefore, in order to reduce the difference between the input-side rotational speed and the output-side rotational speed of the clutch mechanism 11 when the clutch mechanism 11 is re-engaged after the shift of the rear transmission mechanism 12, the shift transition speed of the rear transmission mechanism 12 is reduced. or after the shift of the rear transmission mechanism 12, the rotation speed of the input side of the clutch mechanism 11 is controlled to match the rotation speed of the output side of the clutch mechanism 11 after the rear transmission mechanism 12 shifts. The rotational speed of the input side of the clutch mechanism 11, that is, the rotational speed of the output shaft 6 of the engine 1 controls the torque of at least one of the engine 1 and the rear motor 2 that can apply torque to the output shaft 6. can be changed by The torque required to change the rotation speed of the output shaft 6 is the total moment of inertia of the rotating members connected to the output shaft 6 of the engine 1 and the output shaft 6 with the clutch mechanism 11 released. It can be obtained by multiplying the change rate of the rotation speed required when changing the rotation speed .

Further, when the vehicle is traveling with the EV traveling mode set, the engine 1 and the rear motor 2 are stopped. Alternatively, although the engine 1 and the rear motor 2 are driven in order to convert the power of the engine 1 into electric power by the rear motor 2, the number of rotations thereof does not match the number of rotations on the output side of the clutch mechanism 11. Not exclusively. Therefore, when there is a request to switch from the EV driving mode to the engine driving mode, the input side rotation speed and the output side rotation speed of the clutch mechanism 11 will At least one of the engine torque and the motor torque is controlled so that

FIG. 2 shows a case in which the rotational speed of the output shaft 6 of the engine 1 is controlled to decrease as the rotational speed of the output side of the clutch mechanism 11 is decreased by upshifting the rear transmission mechanism 12. 1 shows an example of changes in the target rotational speed of the output shaft 6 and changes in the actual rotational speed. In the example shown here, the rotational speed of the output shaft 6 of the engine 1 is the same as the input rotational speed of the clutch mechanism 11. Therefore, in the following description, the input rotational speed is simply referred to as the output side of the clutch mechanism 11. is simply referred to as output rotation speed.

In the example shown in FIG. 2, at time t0, which is before the rear transmission mechanism 12 is upshifted, the target value of the input rotation speed indicated by the solid line and the actual value indicated by the broken line match at a relatively high rotation speed. . In order to match the input rotation speed with the rotation speed after the upshift, the target rotation speed starts to decrease gradually from time t1. Therefore, the actual input rotation speed begins to decrease almost at the same time as the target rotation speed. That is, at least one of the engine torque and the motor torque is subjected to feedback control such as PID control using the difference between the target rotation speed and the actual rotation speed as a variable, thereby reducing the actual input rotation speed. I am letting The combined torque obtained by combining the engine torque and the motor torque at that time is controlled so as to be smaller driving torque or braking torque than resistance torque such as sliding resistance.

At time t2, the rotation speed after the upshift matches the target rotation speed, so that the target rotation speed is kept constant. On the other hand, in the example shown here, the actual number of revolutions overshoots the target number of revolutions, resulting in a number of revolutions lower than the target number of revolutions. Therefore, after time t2, feedback control is continuously executed so that the actual rotation speed follows the target rotation speed, and as a result, the target rotation speed and the actual rotation speed match at time t3.

In order to make the actual input rotation speed follow the target rotation speed as described above, at least one of the engine torque and the motor torque should be controlled. That is, it is sufficient to control the torque of any device that applies torque so as to change the input speed. In the following description, a device that applies torque to an object whose rotational speed is to be controlled is collectively referred to as a torque applying device.

On the other hand, as described above, the higher the engine speed, the better the engine torque response. may become Therefore, the control device according to the embodiment of the present invention selects a torque addition device having a good torque response according to the operating state of the torque addition device, determines the feedback torque of the torque addition device, and then determines the requested torque. It is configured to determine the feedback torque of the other torque applying device in order to satisfy the feedback torque of the other torque applying device.

A flow chart for explaining an example of the control is shown in FIG. The example of control shown in FIG. 3 is an example of control for determining the engine torque and the motor torque in the shift transition period. First, the target engine speed is obtained (step S1). In this step S1, for example, while the clutch mechanism 11 is disengaged for gear shifting, when the input rotation speed is made to match the output rotation speed after gear shifting, the engine can be driven by a change in engine sound caused by a sudden change in the engine rotation speed. The change rate of the rotation speed is determined according to the user's comfort, etc., and the current routine is set based on the change rate of the rotation speed and the elapsed time since the start of changing the input rotation speed. Obtain the target engine speed.

Next, a feedback torque (hereinafter referred to as the requested FB torque) is obtained based on the target engine speed and the actual engine speed (step S2). The required FB torque in step S2 is the amount of change in the torque (composite torque) acting on the output shaft 6 to reduce the difference between the actual engine speed and the target engine speed. The difference between the number and the actual engine speed is obtained, and the difference in speed is divided by the allowable time for reducing the difference in speed. It can be obtained by multiplying the total moment of inertia of the rotating member.

After step S2, it is determined whether or not the motor torque response is better than the engine torque response (step S3). The responsiveness of the motor torque is determined based on the characteristics of the rear motor 2, the characteristics of the inverter 7 connected to the rear motor 2, or the like. Specifically, for example, since the rate of change of the motor torque is limited in order to prevent the temperature of the inverter 7 from rising excessively, the responsiveness of the motor torque is adjusted according to the rate of change of the motor torque. is defined. On the other hand, since the ignition timing of the engine 1 is generated periodically according to the crank angle, the higher the engine speed, the better the responsiveness of the engine torque. Therefore, when the engine speed is relatively low, the responsiveness of the motor torque is better than the responsiveness of the engine torque. If the engine speed is high, the responsiveness of the engine torque is better than the responsiveness of the motor torque, so a negative determination is made in step S3. Therefore, step S3 may be determined based on whether the engine speed is less than a predetermined speed. Note that the torque responsiveness is the time from when the torque command signal is output from the ECU 21 to when the torque corresponding to the command signal is actually output.

If the responsiveness of the motor torque is better than the responsiveness of the engine torque and the determination in step S3 is affirmative, the amount of change in the motor torque for causing the actual engine speed to follow the target engine speed. (hereinafter referred to as motor FB torque) is determined within the range of the limited torque of the rear motor 2 (step S4). That is, feedback control is preferentially executed by changing the motor torque.

Even if feedback control is preferentially executed by changing the motor torque in step S4, there is a possibility that the motor FB torque cannot satisfy the requested FB torque. In such a case, the engine 1 outputs the insufficient torque. Specifically, following step S4, the amount of change in the torque required for the engine 1 (hereinafter referred to as engine FB torque) is obtained (step S5), and this routine is temporarily terminated. That is, the engine FB torque is obtained by subtracting the motor FB torque from the requested FB torque. If the motor FB torque determined in step S4 can satisfy the required FB torque, then in step S5, the engine FB torque becomes "0". follow the rpm.

On the other hand, if the response of the engine torque is better than the response of the motor torque and the result is negative in step S3, feedback control is preferentially executed by changing the engine torque (step S6). ). That is, the engine FB torque for causing the actual engine speed to follow the target engine speed is determined.

Even if feedback control is preferentially executed by changing the engine torque in step S6, there is a limit to the period in which the ignition timing of the engine 1 can be changed, and there is a possibility that the engine FB torque cannot satisfy the requested FB torque. . In such a case, the insufficient torque is output from the rear motor 2 . Specifically, following step S6, the motor FB torque is obtained (step S7), and this routine is temporarily terminated. That is, the motor FB torque is obtained by subtracting the engine FB torque from the requested FB torque.

As described above, engine torque can be changed by ignition timing control, fuel injection amount control, and intake air amount control. change speed changes. Therefore, for example, in step S6, first, the maximum amount of change in engine torque by changing the ignition timing is obtained, and if the maximum amount of change in engine torque cannot satisfy the required FB torque, the fuel injection amount is reduced. The maximum amount of change in engine torque due to the change is added to the maximum amount of change in engine torque due to the change in ignition timing, and if the added amount of change in engine torque cannot satisfy the required FB torque, step The motor FB torque may be obtained by S7. That is, in addition to selecting a torque adding device that first determines the feedback torque based on the torque responsiveness, the control means for outputting the feedback torque by the torque adding device may be selected.

FIG. 4(a) shows an example of the order in which torque responsiveness is good when the engine speed is low. , the control of the fuel injection amount, and the control of the intake air amount, the torque responsiveness becomes better. On the other hand, when the engine speed is high as shown in FIG. 4(b), the control of the ignition timing and the fuel injection amount of the engine 1, which are controlled according to the engine speed, is more important than the control of the motor torque. and the control of the intake air amount becomes the slowest. Therefore, until the sum of the engine FB torque and the motor FB torque becomes the required FB torque, torques that can be output are added in the order shown in FIGS. It may be configured to determine the FB torque. Note that it may not be preferable to change the fuel injection amount due to temperature conditions of a catalytic converter (not shown) for purifying NOx and the like exhausted from the engine 1. In such cases, the fuel injection amount is not changed. is preferred.

As described above, the engine torque responsiveness and the motor torque responsiveness are compared to select a torque applying device (here, the engine 1 and the rear motor 2) that can apply torque to the input rotation speed. Determines the feedback torque of the selected torquing device. The responsiveness of this torque is determined according to the operating state of the torque adding device such as the engine speed. That is, the torque of the appropriate torque adding device is preferentially controlled for outputting the feedback torque. By selecting a torque addition device that outputs feedback torque according to the operating state of the torque addition device that changes moment by moment, such as the engine speed, a torque addition device with good torque responsiveness can generate the feedback torque. that is, the torque acting on the output shaft 6 is changed by a torque applying device with good torque responsiveness. It is possible to suppress an increase in the difference from the target rotation speed. Therefore, the difference between the actual input rotation speed and the target rotation speed can be quickly reduced. In other words, it is possible to appropriately perform feedback control for causing the engine speed to follow the target speed. In addition, since the feedback torque that is insufficient for the requested FB torque is output from the other torque adding device, the requested FB torque can be satisfied.

In the control example described above, the feedback torque of a torque addition device having good torque responsiveness is determined, and the other torque addition device outputs the torque that is insufficient for the requested FB torque. On the other hand, if a torque addition device with good torque response is outputting up to near the limit torque before adding the feedback torque, adding the feedback torque will cause changes in the requested FB torque and the reference requested torque. There is a possibility that a situation such as the inability to change the torque following the Alternatively, the motor torque and the engine torque, which have different torque responsiveness, are cooperatively controlled, which may make the control difficult.

To give a specific example, when the ignition timing is controlled to be retarded, the temperature of the exhaust gas increases. Therefore, when the required torque of the engine 1 based on the amount of accelerator operation is relatively high, the amount by which the ignition timing can be retarded is limited. That is, the amount of decrease in engine torque is limited. In addition, since the output torque of the rear motor 2 is limited by various conditions such as the remaining charge of the power storage device 9 and the temperature of the power storage device 9 and the inverter 7, the rear motor 2 is controlled based on the amount of accelerator operation. When the required torque is relatively high, the amount of change in motor torque is limited. That is, the magnitude of the feedback torque that can be output from the engine 1 and the rear motor 2 fluctuates according to the operating conditions of the engine 1 and the rear motor 2 before the feedback torque is applied.

Therefore, the control device according to the embodiment of the present invention selects the torque addition device that can output a larger torque, determines the feedback torque of the selected torque addition device, and determines the feedback torque of the selected torque addition device. Alternatively, the insufficient feedback torque may be output from the other torque adding device. An example of such control is shown in FIG. Note that steps similar to those in the control example shown in FIG. 3 are assigned the same step numbers, and descriptions thereof are omitted.

In the control example shown in FIG. 5, following step S2, it is determined whether or not the difference between the amount of change in torque that can be output from the rear motor 2 and the amount of change in torque that can be output from the engine 1 is greater than a predetermined value. (Step S11). The amount of torque change that can be output by the engine 1 and the rear motor 2 can be obtained based on the operating conditions of the engine 1 and the rear motor 2 as described above. Note that the predetermined value in step S11 is a determination threshold value and may be "0".

If the difference between the amount of change in torque that can be output from the rear motor 2 and the amount of change in torque that can be output from the engine 1 is greater than a predetermined value, and if the determination in step S11 is affirmative, the process proceeds to step S4. On the contrary, if the difference between the amount of change in torque that can be output from the rear motor 2 and the amount of change in torque that can be output from the engine 1 is equal to or less than a predetermined value, the determination in step S11 is negative. , the process proceeds to step S6.

As described above, the torque adding device that can output a larger torque change amount is selected, and the feedback torque of the selected torque adding device is determined. The amount of change in torque that can be output is determined according to the operating state of the torque adding device such as the engine torque and motor torque before the feedback torque is added. By setting the feedback torque of the torque adding device that can output a large torque change amount in advance of the feedback torque of the other torque adding device, the difference between the torque to which the feedback torque is added and the limit torque is small. You can prevent it from becoming Further, if the feedback torque of a torque addition device that can output a torque change amount larger than the required FB torque is large, the feedback torque of a plurality of torque addition devices will not be controlled in a coordinated manner, and the feedback control will be complicated. can be suppressed.

Further, when the clutch mechanism 11 shown in FIG. 1 is a friction type clutch mechanism, by controlling the transmission torque capacity of the clutch mechanism 11, the output torque is output so that the input rotation speed and the output rotation speed of the clutch mechanism 11 match. A torque acts on the shaft 6 . To give a specific example, the flex is started by using the kinetic energy of the engine 1 as power by maintaining the rotation speed of the engine 1 at a high rotation speed while the vehicle is stopped and engaging the clutch mechanism 11 in that state. When performing start or launch control, the clutch mechanism 11 is slipped to apply braking torque to the output shaft 6, thereby suppressing the engine speed from rising above a predetermined speed. That is, the clutch mechanism 11 is a device that applies torque to the rotating member that is the target of rotational speed control.

In such a case, if the engine torque or motor torque is controlled to maintain the engine speed at a predetermined speed, the engine torque or the motor torque will be limited. cannot be sufficiently secured. Therefore, the control device according to the embodiment of the present invention controls the transmission torque capacity of the clutch mechanism 11 when the engine 1 or the rear motor 2 is outputting power equal to or greater than a predetermined power with the clutch mechanism 11 released. It is configured to perform feedback control so that the engine speed follows the target speed.

An example of such control is shown in FIG. Note that steps similar to those in FIG. 3 are assigned the same step numbers, and descriptions thereof are omitted. In the control example shown in FIG. 6, following step S2, it is determined whether or not the driving force is prioritized (step S21). This step S21 is a step for determining whether or not it is necessary to maintain the power of the engine 1 and the rear motor 2 at a predetermined power. If so, it means that the driving force is prioritized, and the determination in step S21 is affirmative. Conversely, if the flag for flex start or launch control is turned off by other control, a negative determination is made in step S21. In other words, it is determined whether or not the motive power (operating state) of the engine 1 and the rear motor 2 is in a situation where the motive power is relatively high or higher.

If the determination in step S21 is affirmative because the driving force is prioritized, the transmission torque capacity of the clutch mechanism 11 for causing the actual engine speed to follow the target engine speed (hereinafter referred to as clutch FB torque) is determined within the range of the limited torque capacity in consideration of the durability of the clutch mechanism 11 (step S22). That is, feedback control by changing the transmission torque capacity of the clutch mechanism 11 is preferentially executed.

Even if feedback control is preferentially executed by changing the motor torque in step S22, there is a possibility that the clutch FB torque cannot satisfy the required FB torque. In such a case, the insufficient torque is output from the engine 1 or the rear motor 2 . Specifically, following step S22, the engine FB torque or the motor FB torque is obtained (step S23), and this routine is temporarily terminated. That is, the engine FB torque or the motor FB torque is obtained by subtracting the clutch FB torque from the required FB torque. Therefore, when the clutch FB torque determined in step S22 can satisfy the required FB torque, in step S23, the engine FB torque and the motor FB torque become "0", so only the transmission torque capacity of the clutch mechanism 11 to make the input rpm follow the target rpm. It should be noted that which of the feedback torque, the engine feedback torque and the motor feedback torque, is determined in step S23 is determined based on the control examples shown in FIG. 3 or FIG. Even in that case, if the requested FB torque cannot be satisfied, the feedback torque of the other torque adding device may be obtained.

On the other hand, if the determination in step S21 is negative because the driving force is not prioritized, the feedback control is preferentially executed by changing the engine torque or motor torque (step S24). That is, the engine FB torque and the motor FB torque for causing the actual engine speed to follow the target engine speed are determined.

Even if the feedback control is preferentially executed by changing the engine torque or the motor torque in step S24, there is a possibility that the engine FB torque or the motor FB torque cannot satisfy the requested FB torque. In such a case, braking torque is applied to the output shaft 6 by controlling the transmission torque capacity of the clutch mechanism 11 to compensate for the insufficient torque. Specifically, following step S24, the clutch FB torque is obtained (step S25), and this routine is temporarily terminated. That is, the clutch FB torque is obtained by subtracting the engine FB torque or the motor FB torque from the required FB torque. It should be noted that whether the feedback torque of the engine FB torque or the motor FB torque is determined in step S24 can be determined based on the control examples shown in FIGS. 3 and 5, as in step S23.

As described above, when the driving force is prioritized, the clutch mechanism 11 is selected as the torque applying device, and the feedback torque of the clutch mechanism 11 is determined. By setting the feedback torque of the clutch mechanism 11 prior to the feedback torque of the engine 1 and the rear motor 2 in this manner, the torque of the engine 1 and the rear motor 2 is reduced in order to control the rotational speed of the output shaft 6. can be suppressed. That is, the engine 1 and the rear motor 2 can continue to output large power. Therefore, it is possible to output driving force according to the requirements such as flex start and launch control.

The vehicle is not limited to the configuration in which the engine and the motor are connected to the output shaft whose rotation is to be controlled, and torque can be applied to the rotating member whose rotation is to be controlled from a plurality of devices. Any vehicle is acceptable. To give a specific example, in the case of a vehicle equipped with a differential mechanism that connects an engine, a motor, and an output member so that they can rotate differentially, the balance between the engine torque and the motor torque determines the engine speed. is controlled, the engine speed can be controlled by controlling the torque of the engine or motor. Therefore, even in the case of such a vehicle, the rotational speed of the engine output shaft can be controlled by outputting feedback torque from one of the engine and the motor according to the operating conditions of the engine and the motor. can be done.

Further, the vehicle according to the embodiment of the present invention is not limited to a hybrid vehicle having an engine and a motor as driving force sources. and an engaging mechanism capable of applying torque to the rotating member.

Reference Signs List 1 engine 2 rear motor 3 rear drive device 6, 13, 17 output shaft 11 clutch mechanism 12 rear transmission mechanism 21 electronic control unit (ECU)
Vehicle

Claims (4)

An engine and a motor coupled to an output shaft of the engine are provided , and a target rotational speed of the output shaft is controlled by controlling a combined torque obtained by synthesizing torques output from the engine and the motor. A vehicle rotation speed control device configured to adjust the rotation speed,
A controller that controls the output torque of the engine and the motor ,
The controller is
obtaining a target amount of change in the combined torque required to reduce the difference between the actual number of rotations of the output shaft and the target number of rotations of the output shaft ;
Responsiveness of the torque of the motor changes according to the operating conditions of the engine and the motor when the difference between the actual rotation speed of the output shaft and the target rotation speed of the output shaft is reduced. is better than the torque responsiveness of the motor, the amount of change in the torque to be applied to the output shaft by the motor is determined , and the target amount of change in the combined torque and the output shaft by the motor determining the amount of change in the torque applied to the output shaft by the engine based on the amount of change in torque to be applied ;
According to the operating conditions of the engine and the motor when the difference between the actual rotation speed of the output shaft and the target rotation speed of the output shaft is reduced, the response of the torque of the engine changes the response of the torque of the motor. If it is better than the performance, determine the amount of change in the torque applied to the output shaft by the engine, and based on the target amount of change in the combined torque and the amount of change in the torque applied to the output shaft by the engine , determining the amount of change in the torque applied to the output shaft by the motor;
A rotation speed control device for a vehicle characterized by being configured as follows. A vehicle rotation speed control device according to claim 1 ,
The controller is
determining that the torque responsiveness of the motor is better than the torque responsiveness of the engine when the rotational speed of the engine is less than a predetermined rotational speed;
It is configured to determine that the torque responsiveness of the engine is better than the torque responsiveness of the motor when the number of revolutions of the engine is equal to or higher than the predetermined number of revolutions. vehicle rotation speed control device. The vehicle rotation speed control device according to claim 1 or 2,
The engine is configured such that an ignition timing for igniting a mixture of supplied air and fuel is controlled according to a rotation angle of an output shaft of the engine,
A rotation speed control device for a vehicle, wherein the torque applied to the output shaft is changed by changing the ignition timing from a predetermined timing. A vehicle rotation speed control device according to any one of claims 1 to 3 ,
The engine is configured to supply fuel to the engine according to the rotation angle of the output shaft;
A rotation speed control device for a vehicle, wherein a torque applied to the output shaft is changed according to an amount of fuel supplied to the engine.

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